1. Field of the Invention
The present invention relates to systems for isolating toxins and collecting an eluate for subsequent testing and to methods of isolating toxins and collecting an eluate using the same systems. More particularly, the present invention relates to systems for isolating toxins and collecting an eluate from a column for subsequent testing and to methods of isolating toxins and collecting an eluate using the same systems, wherein some amount of pressurized gas is continuously being delivered to the headspace of the column even when a fluid is not being forced through the resin gel in the column.
2. Background Art
The presence of microbial pathogens is a well-recognized cause of various medical and etiological problems. For example, microscopic fungi can produce toxins e.g., mycotoxins, that can be ingested, causing severe health complications and discomfort. These toxins can cause, among others, blood disease, cancer, nervous system disorders, kidney damage, and liver damage. Many of these fungi, can grow on plants, especially plants that produce grains for human and animal consumption. Thus, food contaminated with mycotoxins presents a serious health risk for humans as well.
e.g., grain, milk, food products, early on and quickly and with a high degree of certainty and at a high throughput.
Advanced bio-analytical toxicology screening is an essential part of quality food processing. This is especially true with respect to testing for aflatoxins, the predominant carcinogenic toxin found in the food supply. Vicam, Incorporated of Watertown, Mass. provides the food quality industry with methods and means for analyzing aflatoxins using an immuno-affinity column, i.e., the Afla-Test® column. U.S. Pat. Nos. 4,859,611 and 4,818,687 that disclose the Afla-Test® column are incorporated herein by reference.
The immuno-affinity column is substantially cylindrical in shape and open at both ends. A resin gel portion is interposed inside the column cylinder, between the two open ends. The resin gel comprises a multiplicity of beads to which antibodies, e.g., monoclonal, polyclonal, and the like, are covalently bonded. A sample extract can be placed in the upper portion of the column and a low-pressure gas, preferably an inert gas (air), applied to the sample in the upper portion, or headspace, of the column to force the sample through the resin gel to the lower portion of the column.
In a particular use, antibodies demonstrating a high affinity for aflatoxin types, e.g., B1, B2, G1, G2, M1, and some metabolites, and other mycotoxins can be used. These particular high-affinity aflatoxin antibodies are described illustratively, however, and are not to be construed as limiting the full scope and spirit of this disclosure. As the sample percolates through the gel or is forced through the gel under an applied pressure, any or most of the aflatoxins in the sample will retain, i.e., bound, by the antibodies in the gel portion. The soluent that passes the resin gel portion can be discarded.
If the resin gel is then washed, e.g., using distilled water, to remove non-toxins that may have been retained in the resin gel and, further eluted, e.g., using high performance liquid chromatograph (“HPLC’) grade methanol, the methanol solution will remove any aflatoxins retained by the antibodies and the resulting eluate can be collected and tested, e.g., in a liquid chromatograph, fluorometer, a mass spectrometer or the like, to determine the presence of toxins. For example, a developer could be added to the eluate and the eluate placed in a fluorometer.
When conditions require extensive testing for quality food processing, e.g., testing representative samples of all incoming grain at a grain elevator, high throughput is essential to avoid backing up trucks and tractor trailers, rail cars, and/or river barges delivering grain to the elevator at harvest time. Therefore, it would be desirable to provide an economical, high throughput, system for collecting and preparing samples for testing for pathogens.